[HADOOP-13163] Reuse pre-computed filestatus in Distcp-CopyMapper

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.8.0
• Fix Version/s: 2.8.0, 3.0.0-alpha1
• Component/s: tools/distcp
• Assignee: Rajesh Balamohan
• Reporter: Rajesh Balamohan
• Created: 17/May/16 04:34
• Updated: 30/Aug/16 05:55
• Resolved: 17/May/16 12:16

Description

https://github.com/apache/hadoop/blob/af942585a108d70e0946f6dd4c465a54d068eabf/hadoop-tools/hadoop-distcp/src/main/java/org/apache/hadoop/tools/mapred/CopyMapper.java#L185

targetStatus is already computed and it can be reused in checkUpdate() function. This wouldn't be a major issue in NN/HDFS, but in the case of S3 getFileStatus calls can be expensive.